Paddle wheel for steamers



.May 14, 1929. F. SBERKRB PADDLE WHEEL FOR STEAMERS 2 sheets-sheet 1 Filed April 23, 192e A fr?,

May 14, 1929. F. sBl-:RKRB

PADDLE WHEEL FOR STEAMERS Filed April 23, 1928 2 Sheets-Sheet 2 Patented May 14, 1929.

UNITED STATES FRANZ SBERXBB, OF HAMBURG, GERMANY. y

PADDLE WHEEL Application led April 23, 1828, Serial lo.

As is understood, the -speed of paddle wheels for Steamers is limited, for the reason that when argiven speed is exceededan excessive volume of air is entrained inthe wake of the blades, preventing the` surrounding water from flowing in with sufiicient rapidity A to fill the void behind the blade so that the succeeding blade encounters a mass of mixed air and water, thus diminishing the resistance of the water to the blade, reducing the efliciency of the paddle wheel. This lack of eiliciency is the more noticed the more rapidly the paddle wheel is rotated. By way of eX- ample on river Steamers of 1300 H. P.. or so the paddle wheels, having a diameter' of 31/2 metres and blades of a breadth of 1 metre and a depth of immersion of 1.3 metres are limited to a'speed of but 33 revolutions per minute o'n account of the cavitation arising at higher speeds. e Y

' The object ofthe invention is to construct a paddle wheel of the type which works with only `a segmental portion thereofsubmerged which may he given a'higher circumferential speed than was'heretofore practicable withv i 'out reduction in its efficiency lVhereasin known paddle wheels the folg lowing up of the water to the rear of the l, blades is prevented, forthe reason that lthe blades work at or near the Water level, and thus draw air from the 'surface into the void behind the blades, according to the present invention the blades are so guided that on dipping into or entering the water their faces are adjustedv approximately tangentially to .the periphery of the wheel, so that they cut the current induced by the forward motion of the vesselat such an anglethatzthey cannot perform work and that they only radually come into radial position and per orm propulsive work when immersed to sucha depth Y that the column orlayer of water above the upper edge ofk the blade is deep enough, to

be impenetrable by the surface air. The entraininent of air may be further prevented by making the blades of comparatively small breadth. The breadth should notexceed 55% of the depth of immersion. The result will bethat the blades can vbepulled through the water with a greater speed, and thus the circumferential speed of the paddle wheel may be considerably increased, itV being Vknown that the resistance offered to the `blades by the water increases withthe square'ofthe speed.

' air. According the water isA so shallow that the.:

ron emmene.'

272,295, and in Germany october s, m1.

blades cannot work at such a depth that there would be a sulicient column of'water above to be impenetrable to air, further provlsion -1s made to prevent entrainment of to the invention there is arranged at a level a horizontal cover plate through slots or gaps in which the blades passdown at the forward Aend and up again at the outer-end, means being preferably provided for closing sight depth belowy the water v the slots more or less after each blade has .passed and for opening them again when the next following blade approaches. l

To prevent air from entering from the sides of the wheel the cover plate may be connected with segmental vertical plates at both sides and concentric therewith arcuate segments fixed to the paddle box, so that air cannot penetrate the water flowing under the horlzontal cover plate. Y

The horizontal cover plate maybe of such forIn-thatit serves to guide the water passing plained low. Y. Y

The intermediate section of the cover plate section is suspended from the paddle wheel shaft, and connected witha sun wheel loose on .the said shaft, while on the, boss ofthe paddle wheel or blade-carrying disk is 'l mounted one or more .shafts carrying one or more lanetary wheels engaging 'with said sun-Weel, said last-mentioned shafts carrying a secondset of lanet'aryvwwheelsv` engaging a second'sun-w eel of t sarneprsize as 4the first sun wheel and fixed'to the hullof.

" the ship.

` In the accompanying drawings Fig. 1 isan velevation of a paddle wheel constructed according to the 'present'invention, the paddle boX being shown in section. f

Fig.v 2 1s a cross-section ofthe paddle wheel shownfin Fig.' 1.`v y v f Y Fig..3 illustrates the various'positions of a float about the circumference of the wheel, and

Fig. 4is

ypivot b of each blade a an arme carrying to the. `'addles,as"will*be more fully exan enlargement of that part of Fig. -r `3 'where the float dips into the water.

at its outer ,end a roller d tracking a cam groove e on the hull f of the ship. As will Abe seen from'Figs. 3 and 4, the groove is so sha ed that Onentering the water the 4face ofY blade is approximately tangential to i the periphery of the wheel. If theV circumferential speedot the paddle Vwheel be F ig.

t, Vandthe speed of the ship be y, then theV resultant z vrepresents l the direction in kwhich the blade can pass through the water without doing work.V vSuch idle movement of Y,the

blade isinaiiitained until the float is iniinersed toa depth. beyond which air cannot 'penetrate. v Beginning at this point the blade is so guided-that it performs work in propellingthe vesselg- -The positions 'between which the'blade'do'es no work on entering the l' vater are indicated by l vand 2; inthe posijustedthat no work is done and ne water to speak of willf'be thrown into the air.

If the steamer is'to be navigated in very shallow water, so that there is only very little depth of water for the blade Vto operate in, provision must bejmade to render the blade feiliective. even in shallow water. To this end the invention contemplates the iise of a horizontal cover plate g which is preferably :niadein three VsectiensV g', vg2 and gsjo't which sections g and are Varrangedoutsideand g2 inside the wheelbelow the lwat-er. leve'l.

which the 'bladesjare to perform work.

The cover platefprotects the water rom penetration'by the surface airvto the :depth at It is of advantaget :close thegap's between the sections g and g2 and'between the sections g2; and g3 Ithe moment` a blade has passed and to reopen the gaps when another blade ap'- proaches the saine to permit the -passage oi p the other. blade.Y The movement of the said sections ymaybe effected Vin anyconvenient manner. intheconstruction shown. in Figs.

'l 1 and 2 th'e'sections g and g3 are suspended Y on vertical rods or arms [L connected to pivots on the paddle box el." Springs c litted to the paddle box bear yieldingly against thearms 7L tov press them against the rim of the dise/m,

thus normally closing the gaps Abeti'v'een the sections gand g3 and between the sections y' Cams a on the periphery oi the g2 and g3.

' disem at suitable distances from the axes ofV the blades (zo-operate with rollers 0 on the arms 71 to move the arms in opposition to the springs 7c whereby the section g or g3 respectively is moved away from the sect-ion blade to pas Y The'inner section g2 is mounted on arms .(/2 when thegap is to be opened to allow the p which hang loosely on the Ishaft g oi the ypaddle wheel. Fixed to one arm p 'and also loose yon the shaft'lg is atoothed wheelV 1" planetary .gearing and cQ-eperatingwithy one or 'more planetary wheels s', the shafts u of Veillectivel'y prevented. v f

i l to initial position. -(Fig.2) constituting the sun wheel of a' which are rotatably journalled in the boss m of the paddle wheeler in one of the discs m. VT he shafts u carry on the other side oi ,Y the disc lml a secondset of planetary wheels s co-operative with a ysecond sun-wheel fr fixed tothe hull f of the ship. rl`he sun-wheel -2 being iXedly mounted, the sun wheel fr inust also remain vat rest and consequently the plate g2 is held stationary. f Y

It is of advantage to provideineans for preventing theV penetration of air to the blades from the side if the' depth oit immersion is very small. T.lVith this object in View, vertical cover plates-are provided on the inside as well plates the entranceot air from the side is The horizontal coverplates may be so constriictedtliat'they serve as guides for the water passing to the iioats when-in` operation. Owing to the waves Vcreated by the ship as well as yby the rotation of the paddle wheel` the water does'not flow exactly parallelto' the floats in the plane of the water line and'therefore the eiiiciency of the loats is diminished.

i In order to Vincrease the eiiiciency the' cover 'plate 'g lor sections thereof are given such inclination that they serveas guides. F ig. 5

illustrates a modiiication'inwhich the outer cover plate sections are suitably inclined. 'It

Vdesired also Vthe inner section g2 may befin- .clined correspondingly.'A A cover plate of this description or parts thereof may be even used'on' slow running paddle wheels for regulating the flowot'the water to the floats as described above. i w

'l I claim l 'Y l. A paddle wheel characterized by a cover plate intermediate thewater line and the operative position of theblades, said plate serv-V ing to hold back the air.

2.'A paddle 'wheelaccording to claim l,l

further characterized in that-the cover plate is .of such a size thatit projects from the lwheel at thek front and attlie rear end presents plate are connected Vwith adevice which on Y' the yapproach of the blades moves such parts to allow the blades to pass and then returns them 5. A paddle wheel according to claim 1v fur- K ther characterized inthatthatpart of theV cover plate which is arranged within thewheel is provided with segmental plates at right angles thereto, and arcuate cover plates arranged coneentriel With said segmental plates.

6. An anti-Cavitation paddle Wheel for Steamers, of the type adapted to have only a segmental portion submerged, including submersible feathering blades, and means for changing the angularity of the blades, said means being Constructed to position each blade so as to cause it to enter the Water in a direction substantially normal to the Water surface, said means maintaining each blade in such position as to submerge idly until the depth of Water above its upper edge is depth, that when the blade is in its lowermost position, the depth of WaterY above the upper edge of the blade is at leastl equal to the breadth of the blade.

In testimony whereof I have signed my name to this specification.

FRANZ SBERKRB. 

